The inner wall of the mixing drum of the concrete mixer is usually provided with a pair of ribbon spiral blades, which are installed at an angle of 180 °, and the left-hand blades are used. When the mixing drum rotates, the two spiral blades are moved around the mixing axis to realize the feeding, mixing and unloading of concrete. The mixing drum can be divided into two sections according to its function. The tail cone outlet section is the unloading guide section. The cylindrical part and the front cone part are mainly used to stir the concrete during transportation to prevent solidification and segregation, and push out the bottom concrete during unloading.

圓錐螺旋面是指母線aa′繞圓錐中心軸線、沿筒壁螺旋線軌跡旋轉(zhuǎn)，母線的運(yùn)動(dòng)軌跡所形成的圓錐螺旋面。母線為直線的形成直紋螺旋面，母線為曲線的形成非直紋螺旋面。在直紋螺旋面中，母線與圓錐中心軸線正交的，形成直紋正螺旋面；母線與圓錐中心軸線斜交形成直紋斜螺旋面。

Conical spiral surface refers to the conical spiral surface formed by the movement track of the generatrix AA 'rotating around the central axis of the cone and along the spiral track of the cylinder wall. Straight spiral surface is formed when the generatrix is a straight line, and non straight spiral surface is formed when the generatrix is a curve. In the ruled helicoid, the generatrix is orthogonal to the central axis of the cone to form the ruled regular helicoid; The generatrix is obliquely intersected with the central axis of the cone to form a ruled inclined spiral surface.

你以為攪拌車(chē)筒體有兩條螺旋線，其實(shí)筒體內(nèi)共設(shè)置了9條螺旋線，即前錐部分葉片葉根螺旋線（螺旋線1）和葉頂螺旋線（螺旋線4），圓柱部分葉片葉根螺旋線（螺旋線2）和葉頂螺旋線（螺旋線5），尾錐部分葉根螺旋線（螺旋線3）、葉中螺旋線（螺旋線6和螺旋線8）、葉頂螺旋線（螺旋線7和螺旋線9），其中螺旋線8和螺旋線9為圓柱部分與尾錐部分的過(guò)渡螺旋線。

You think there are two helixes in the mixer cylinder. In fact, there are nine helixes in the cylinder, namely, the blade root helix (helix 1) and blade top helix (helix 4) in the front cone, the blade root helix (helix 2) and blade top helix (helix 5) in the cylindrical part, the blade root helix (helix 3) in the tail cone and the helix in the blade (helix 6 and helix 8) and blade top helix (helix 7 and helix 9), wherein helix 8 and helix 9 are the transition helix of cylindrical part and tail cone part.

這些攪拌筒螺旋線的根部和頂部型式、螺旋角決定混凝土在攪拌筒內(nèi)沿軸向或切向運(yùn)動(dòng)的強(qiáng)度，因而也影響著攪拌和卸料的性能，是攪拌筒設(shè)計(jì)的關(guān)鍵。

The root, top type and spiral angle of these spiral lines of the mixing drum determine the strength of the concrete moving along the axial or tangential direction in the mixing drum, which also affects the performance of mixing and unloading, which is the key to the design of the mixing drum.

攪拌筒螺旋線葉片設(shè)計(jì)原則

Design principle of spiral blade of mixing drum

攪拌葉片的設(shè)計(jì)一般以順時(shí)針轉(zhuǎn)動(dòng)作為進(jìn)料和攪拌，逆時(shí)針旋轉(zhuǎn)作為出料。進(jìn)料時(shí)攪拌筒的轉(zhuǎn)動(dòng)速度較快，為的是節(jié)省工作時(shí)間，攪拌時(shí)攪拌筒的轉(zhuǎn)動(dòng)速度較慢，為的是減少水分過(guò)快地蒸發(fā)，減少離析。但是在運(yùn)輸?shù)倪^(guò)程中攪拌筒必須以恒定速度運(yùn)轉(zhuǎn)，為的是使混凝土不凝固變質(zhì)。在簡(jiǎn)體轉(zhuǎn)動(dòng)的過(guò)程中混凝土被葉片連續(xù)不斷地推送到攪拌筒的前部，到達(dá)前端的混凝土勢(shì)必又被攪拌筒的端壁頂推反轉(zhuǎn)回來(lái)，這樣混凝土做前后的翻滾運(yùn)動(dòng)；兩條葉片不停的旋轉(zhuǎn)帶動(dòng)混凝土連續(xù)的旋轉(zhuǎn)，同一位置上的混凝土通過(guò)這種運(yùn)動(dòng)發(fā)生連續(xù)不斷的變化，從而起到攪拌作用；另外，葉片形狀曲線型的變化可使混凝土在其根部與筒壁之間形成一個(gè)個(gè)小的循環(huán)運(yùn)動(dòng)，對(duì)攪拌混凝土也起到了一定的作用。當(dāng)混凝土運(yùn)輸?shù)焦ぷ鞯攸c(diǎn)，攪拌筒將做逆時(shí)針旋轉(zhuǎn)，此時(shí)葉片的旋轉(zhuǎn)方向也相反，混凝土將會(huì)被葉片引導(dǎo)向攪拌筒口移動(dòng)，直從筒口卸出。

The design of the mixing blade generally takes clockwise rotation as the feed and mixing, and counterclockwise rotation as the discharge. During feeding, the mixing drum rotates faster to save working time. During mixing, the mixing drum rotates slower to reduce the excessive evaporation of water and reduce segregation. However, during transportation, the mixing drum must operate at a constant speed to make mixing The concrete does not solidify and deteriorate. During the rotation of the shell, the concrete is continuously pushed to the front of the mixing drum by the blades, and the concrete reaching the front end is bound to be pushed back by the end wall of the mixing drum, so that the concrete does the rolling movement before and after; the continuous rotation of the two blades drives the continuous rotation of the concrete, and the concrete at the same position occurs continuously through this movement In addition, the change of blade shape curve can form a small circular movement between its root and cylinder wall, which also plays a certain role in mixing concrete. When the concrete is transported to the working place, the mixing cylinder will rotate counterclockwise. At this time, the rotation direction of the blade is also opposite, and the concrete will be guided by the blade Move to the mixing drum mouth until it is discharged from the drum mouth.

螺旋葉片對(duì)攪拌質(zhì)量的影響

Effect of spiral blade on mixing quality

以前，混凝土罐體生產(chǎn)企業(yè)在螺旋葉片的安裝過(guò)程中，由于沒(méi)有使用優(yōu)化技術(shù)，沒(méi)有先在板料上噴粉畫(huà)線后切割卷圓，再沿著卷圓在罐體上形成的螺旋葉片母線進(jìn)行安裝，而是完全憑工人的生產(chǎn)經(jīng)驗(yàn)進(jìn)行焊接安裝，導(dǎo)致安裝完成后形成以螺旋線為母線的不合理的螺旋葉片，得到的罐體成形尺寸精度較差，進(jìn)而影響到了進(jìn)出料速度，使出料率較低。

In the past, in the installation process of spiral blades, concrete tank manufacturers did not use optimization technology. They did not spray powder and draw lines on the plate before cutting the winding circle, and then install the spiral blade bus formed on the tank along the winding circle. Instead, they welded and installed it completely based on the production experience of workers, resulting in unreasonable spiral with the spiral line as the bus after installation The forming dimensional accuracy of the can body obtained by rotating the blade is poor, which affects the feeding and discharging speed and makes the discharging rate low.